Field-spool for electric motors.



E. H. ANDERSON.

FIELD SPOOL FOR ELECTRIC MOTORS.

APPLIGATION FILED JAN.11, 1904.

Patented Apr. 6, 1909.

I 2 SHEETS-SHEET 1.

In ve mt or. Edward l-lflnderson Fig.1.

Witnesss. M

B. H. ANDERSON. I FIELD SPOOL FOR ELECTRIC MOTORS. AP'PLIOATION FILED JAN.11, 1904.

- 916,961. s I Patented Apr. 6, 1909.

Witnesses. Inventor.

Edward |-Iflnderson M W Aug.

U TTED STATES PATENT imiuon.

EDWARD H. .nvnnnsor, or SCHENECTADY, NEW YORK, asslo von TO enxnna ELECTRIC 4 GOMPANKA CORPQRATION on NEW YORK.

FIELD-SPOOL FOR nLEoTnI'o MOTORS.

Specification of Letters Patent. Patented April 6, 1909.

Application filed January 1-1, 1904. Serial No. 188,475. I

To all whom it may concern:

Be it,rknown that I, EDWARD H. ANDER- but such tendency is neutralized by the field son, a citizen of the United States, residing spools which constitute short-circuitcd secat Schenectady, in the county of Schenec-. ondaries in close inductive relation to the tady and State of Xew Yorln have invented field coils and largely destroy their self-in- 0 certain new and useful Improvements in du ction. as the 111:1Q1)()lTOlllOilYQ-fOlCC due to' FieldrSpools for Electric Motors, of which currents induced in the spools is opposed to the-following isa specification. that duetothe licld coils. The opposition lily invention relates to direct-current in the motor circuit to current flow is thereelectric motorsand has for its object the preiore practically reduced to the ohmic rcsislvention of flashing at the commutator when ance' of the windings and connections. -8. the motor circuit is opened and closed. I further result ot' the opposing magnetohave discovered that such flashing may be motive-force set up by the spools. is that the prevented by the use of a novel form of in illl'OUQ'lllll'e armature'is greatly cut spool for the field .coils of the motor. down. Moreover, the armature is revolving Spools of metal may be m-ade light and at a comparatively high rate of speed and strong, and have passed into general use. these conditions are the reverse of desirable As heretofore constructed they have formed for successful operation, as is well undercontinuous metal bands, and therefore closed stood; My invention, by interrupting the electric circuits about the pole piece. Such electric continuity of the spools. operates to 7 construction, however, I have discoveredis preventtheir havingany effect upon the inthe cause of extremely unsatisfactory opera-' duction of the field coils, which field coils tion of direct-current.motors in which it is then act to choke downany rush of current employed, asI will set-forth lYhenever a through the motor and, the IDHQ'HEtOnlOtlVQ- traveling contact, is employed to complete force of said coils being unopposed, a strong ,the circuit of a motor, the circuit isliable to flux through the armature is produced. Sat

be temporarily broken at the contact from a isfactory operation is thus obtained.

variety of causesand this is particularly My invention has proved most efficacious true in connection Withthird-rail systems in remedying the defects recited and the where the current-collecting shoe is often theory of .its operations'is, l believe, as out separated from the supply rail .bygaps at lined, but it may be however, that my invencrossings, joints, or a collection offoreign tion-operates in other ways of which I am matter such as ice, oil,di r't, etc., upon the not aware, to produce the desired results.

mil, If a train operated frdm a third-rail is Referring tothe accompanying, drawings moving along the track with its controllers in which I have illustrated an embodiment fully on, and therefore the motors receiving of my invention, Figure 1 is a partial verfull-line voltage, and the collecting-shoe for tical sectionof a railway mptor, one of the any reason parts from the supply rail, ourfield coils being sectioned so that the applirent will becut off from the motor. The opcation ofiny invention may be seen. The erator having no-kno'w-ledge of thi sfthe conusual commutator brushes and connections. 5 trollers are not disturbed and hence when for the armature havebeen omitted for the i the shoe again comes in contact with the rail sake of 'clea'rness, as their construction and the'full voltage will be again 'npp'lied. When application arewell understood; Fig. 2 is a the electric continuity ofthe "field spools is perspective view of a field'spool'embodying maintained asheretofore the-result; of'such my invention, such as is employedin the 0 application of voltage is an enormous fiow structure illustrated in Fig. 1; Figs. 3 to of current, many time's the "normal value, 7 inclusive are sections of spool flanges which current is liable'to damage then'ioto'r, transverseto the insulating. piece, showing by heating, but the most serious consequence various means by which my invention may is the destructive sparking whichoccnrs, it be carried into effect, and Fig. 8 shows the often becoming so great asto canse arcs 'tomotor and its connectipns somewhat dia-i be formed between the brushes, The causes" grammatically; of this,I believe to be as iollows z- U'pon the Referringto Figs. 1, 2 and 3, A is the application of.the voltage 'the field coils, frame of a motor, tovwhich are secured in I which are in serieswith the armature in rail-. any suitable manner the pole pieces P. B

way motors, tend to choke down the current is the armature of the machine revolving within the pole .pieces P in a well-known manner. Mounted upon the pole pieces in the usual manner are the field spools S, upon which are wound the field coils F which are connected'as shown in Fig.8 in

series with the armaturaas is customary in all standard railway motors. Inserted in each field spool is apiece of insulation 1, which extends from side "to side'l of the spool in such manner that the electric continuity of the spool is broken. In order that the edges of the spool which abut against the insulation may not have relativemovement, depressions as (Z are formed in said edges and projections upon the'insulation register therewith. Lateral bearings are thus formed between the spool edges and the insulation. This is shown more clearly in Fig. 5, which is on an enlarged scale. it will be evident that in this construction it will be impossible for current to fiow about {the spools and therefore the spools cannot {become short-circuited secondaries with re lation t0 the field coils; If desired, instead of inserting a piece of insulation .the continuity of the spool might be interrupted by cutting it through from side to side so that an air gap would be formed. This construction would not, however, be so is inserted, as shown in Figs. 3 to 7 inclusive, in order that sutlicient room for the forming of the projections and depressions may be obtained. In Figs. 3, 4c and 5, vari ous forms of engagement between the edges of the spool. flanges and the insulating piece are shown, It is thought that these figures are selfexplanatoryr In F 6 the outside portions of flanges r are cut away so as to receive the retaining pieces 7) which are separated from the spool by insulation 1.

broken.

eieeei These pieces ,7) may be made of metal, and are secured to the flange by means of the rivets s, the rivets 8 being countersunk on the inner faces of the flanges 1" in order to form a smooth bearing surface for the coil. In Fig. 7 the construction is obvious.

- In'the manufacture of the spool, theinsulating piece or pieces may be placed in the mold and the spool cast around it or the understood that the apparatus shown in the drawings is only illustrative, and that the invention may be carried out by other means than the specific embodiment which I have shown.

hatl claim as new, and desire to secure by Letters Patent of the United States, is,

l. in an electric motor adapted for operation on direct currents, the combination with the; pole pieces, of field coils thereon, metal spools for said'coils, an armature connected in seies with said field coils, each of said spools having its electric continuity broken whereby said field coils act as choke coils to prevent sudden wniations of current strength in the motor circuit.

In an electric motor, the combination of a field frame provided with pole pieces,

field coils mounted upon said pole pieces and connected in series with the motor armature, andmetal spools for said coils, each of said spools having its electric continuity 3. in an electric motor adapted for operation on direct currents, armature and field windings connected in series with each other, and metal spools upon which said field windings are arrangcdysaid spools having their circumferential. electrical continuity inter rupted. I I

. In witness whereof, I have hereunto set my hand this 9th day of January, 1904:.

nnwiiun'u. ANDERSON. Witnesses:

G. C. HoLLIsTEn, .I-IELEN Ouronn. 

